A complex form is a lexical entry that has components. Components fields are used to link a complex form to those forms that combine to make up the complex form. Complex forms can be of different types.
How complex forms are displayed in Dictionary depends on a number of factors. A key factor is which view is used.
In a root-based view, complex forms are displayed as indented subentries. They are subordinated (indented) under one or more component entries.
In a lexeme-based view, complex forms are alphabetized with the other headwords, even those that are not complex. As such, there are no "subentries" in this view.
There can be references to complex forms at which point you see them.
In a Hybrid view, complex forms appear as both full entries and possibly as subentries below one or more of their components.
Given that there are a number of factors, here is a high-level overview of the task of adding a lexical subentry.
Create or specify that a form is complex.
Choose the complex form in various fields, such as Subentries (Publication Settings) or Subentries (Senses).
Configure the appropriate view. You will use nodes like Subentries or Minor Subentries.
On the Help menu, point to Resources, and then click Introduction to Lexicography. There you can use find additional conceptual information about subentries.