Either you set a breakpoint in the line after the line, from which the programming modul is invoked and execute then the command GO.
All programming objects will be executed, and the cursor will stay on this breakpoint (assumed that there are not INPUTs in the skipped program chain). The setting and deleting of breakpoints can be done during debugging in the debugger editor.
Or you use the debugger execution control command STEP SKIPSUBLEVEL. Here’s an excerpt from the manual for the Natural debugger (Natural 4.1.4):
When you enter the direct command STEP SKIPSUBLEVEL (or choose PF17) upon a statement which invokes another object (for example, CALLNAT), processing is continued with the next statement line in the interrupted Natural programming object (instead of the first executed statement in the invoked object).
With the command STEP SKIPSUBLEVEL, you can specify a level number n. n is the level of the interrupted Natural object (this is the default) or a superior level. Step mode then continues with the next object at the specified level.
If this command is applied to a statement that does not invoke another object, the Natural Debugger reacts as if the command STEP had been entered.
Level information can be obtained with the command OBJCHAIN as described in the section Navigation and Information.