Migrating Nested groups

Hi there,

I am migrating 2 source domains into 1 target domain, each domain has its own forest.

When it comes to migrating groups it is very confusing to me.

I am migrating all the user accounts first, in multiple migration sessions, leave them disabled on Target.

Then, I have exported all the groups using the object picker, "Select by group membership" to a txt file.

In the group export file, there are many nested groups, which will be migrated to Target domain, but there are many other groups, like default groups and priviledge groups under User OU, that I don't think I should migrate them.

What would be the consequences of not migrating some of those nested groups, do I need to migrate absolutely every single group from source to target domain?