It is not possible to place a assembly copy into a family of assembly if you haven't check the 'Apply edits to all members'.
part1 is in the assembly 1
so a tree would look like this in the brackets I will write the form I need of part1 at each stage
-Assembly 1 (form1)
I'm lost, could you upload a video what you want.
I'm confused too - could you not make Assembly 1 the family of assemblies file with two members, one with part 1 form 1 and one with part 1 form 2? Then to make the drawing of assembly 1 with form 1, use the FOA member that contains part 1 form 1 for the drawing. Then for assembly 2, place assembly 1 into it using the member that contains part 1 form 2, which would then give you Assembly 2 containing assembly 1 using part 1 form 2.