Added bt tree with some subtrees

src/xml/bt_test.xml

+<?xml version="1.0"?>
+<root main_tree_to_execute="BehaviorTree">
+    <!-- ////////// -->
+    <BehaviorTree ID="BehaviorTree">
+        <SequenceStar>
+            <SubTree ID="set_point_to_blackboard" x="x" y="y" z="z" max_vel="max_vel" new_goal="new_goal"/>
+            <Fallback>
+                <Action ID="async_point_to" max_vel="{max_vel}" new_goal="{new_goal}" x="{x}" y="{y}" z="{z}"/>
+                <Condition ID="is_point_to_finished"/>
+            </Fallback>
+            <SequenceStar>
+                <SubTree ID="set_base_frame_black_board"/>
+                <SubTree ID="set_tol_blackboard"/>
+                <SubTree ID="set_urdf_param_blackboard"/>
+            </SequenceStar>
+            <SequenceStar>
+                <Action ID="sync_point_to" max_vel="{max_vel}" x="{x}" y="{y}" z="{z}"/>
+                <Timeout msec="15000">
+                    <Condition ID="is_point_to_finished"/>
+                </Timeout>
+            </SequenceStar>
+        </SequenceStar>
+    </BehaviorTree>
+    <!-- ////////// -->
+    <BehaviorTree ID="set_base_frame_black_board">
+        <SequenceStar>
+            <SetBlackboard output_key="base_frame" value="servo2"/>
+            <Action ID="set_base_frame" base_frame="{base_frame}"/>
+        </SequenceStar>
+    </BehaviorTree>
+    <!-- ////////// -->
+    <BehaviorTree ID="set_point_to_blackboard">
+        <SequenceStar>
+            <SetBlackboard output_key="x" value="0.8"/>
+            <SetBlackboard output_key="y" value="0.7"/>
+            <SetBlackboard output_key="z" value="0.3"/>
+            <SetBlackboard output_key="max_vel" value="0.5"/>
+            <SetBlackboard output_key="new_goal" value="True"/>
+        </SequenceStar>
+    </BehaviorTree>
+    <!-- ////////// -->
+    <BehaviorTree ID="set_tol_blackboard">
+        <SequenceStar>
+            <SetBlackboard output_key="tol" value="0.01"/>
+            <Action ID="set_tolerance" tol="{tol}"/>
+        </SequenceStar>
+    </BehaviorTree>
+    <!-- ////////// -->
+    <BehaviorTree ID="set_urdf_param_blackboard">
+        <SequenceStar>
+            <SetBlackboard output_key="urdf_param" value="r_desc"/>
+            <Action ID="set_urdf_param" urdf_param="{urdf_param}"/>
+        </SequenceStar>
+    </BehaviorTree>
+    <!-- ////////// -->
+    <TreeNodesModel>
+        <Action ID="async_point_to">
+            <input_port default="0.5" name="max_vel"> The maximum velocity for the servos</input_port>
+            <input_port default="True" name="new_goal"> The maximum velocity for the servos</input_port>
+            <input_port default="0.0" name="x"> Point X coordenate on its reference frame</input_port>
+            <input_port default="0.0" name="y"> Point Y coordenate on its reference frame</input_port>
+            <input_port default="0.0" name="z"> Point Z coordenate on its reference frame</input_port>
+        </Action>
+        <Action ID="cancel_point_to"/>
+        <Condition ID="is_point_to_aborted"/>
+        <Condition ID="is_point_to_action_start_fail"/>
+        <Condition ID="is_point_to_fb_watchdog"/>
+        <Condition ID="is_point_to_finished"/>
+        <Condition ID="is_point_to_param_not_present"/>
+        <Condition ID="is_point_to_preempted"/>
+        <Condition ID="is_point_to_rejected"/>
+        <Condition ID="is_point_to_running"/>
+        <Condition ID="is_point_to_set_param_fail"/>
+        <Condition ID="is_point_to_success"/>
+        <Condition ID="is_point_to_timeout"/>
+        <Action ID="set_base_frame">
+            <input_port default="servo1" name="base_frame"> Servo kinematic chain base frame</input_port>
+        </Action>
+        <SubTree ID="set_base_frame_black_board"/>
+        <SubTree ID="set_point_to_blackboard"/>
+        <SubTree ID="set_tol_blackboard"/>
+        <Action ID="set_tolerance">
+            <input_port default="0.001" name="tol"> Inverse kinematic solver tolerance</input_port>
+        </Action>
+        <Action ID="set_urdf_param">
+            <input_port default="robot_description" name="urdf_param"> Ros param where is stored the urdf model</input_port>
+        </Action>
+        <SubTree ID="set_urdf_param_blackboard"/>
+        <Action ID="sync_point_to">
+            <input_port default="0.5" name="max_vel"> The maximum velocity for the servos</input_port>
+            <input_port default="0.0" name="x"> Point X coordenate on its reference frame</input_port>
+            <input_port default="0.0" name="y"> Point Y coordenate on its reference frame</input_port>
+            <input_port default="0.0" name="z"> Point Z coordenate on its reference frame</input_port>
+        </Action>
+    </TreeNodesModel>
+    <!-- ////////// -->
+</root>
+