Stepping Into and Out of a Child Service
Many times, the flow service you are debugging invokes other flow services (child services). In these cases it is useful to step through the individual flow steps within a child service, too. You do this with the Step Into and Step Return commands.
To step into and out of a child flow
2. In Debug view, step to the flow step that invokes the child flow service.
3. In Designer, select Run > Step Into or click 
on the Debug view toolbar. Designer opens the child flow service and selects (but does not execute) the first step.
4. To execute the first step in the child flow service, select Run > Step Over or click 
on the Debug view toolbar. Repeat this step for each flow step that you want to individually execute within the child flow service. 5. If you want to return to the parent flow service without stepping through the entire child, select Run > Step Return or click 
on the Debug view toolbar. Designer executes the remaining steps in the child flow service, returns to the parent, and then selects (but does not execute) the next step in the parent flow. Notes:
If you select
Step Over on the last step in the child flow service,
Designer automatically returns you to the parent.
You can use
Debug to Here to execute up to particular step in the child flow service. Here,
Designer skips all the breakpoints and stops execution at the selected step.
You can use
Step Into to step into a child flow that is nested within a child that you have stepped into.
If you select
Step Return without executing the entire child flow service and the child flow service subsequently contains an enabled breakpoint,
Designer stops debugging when it hits the breakpoint.