You can try with the option in "Admin > Groups > edit your group1 of users > seelct category X by default to the objects created by that group of users".
and then, add the restrictive perms in that category, in order that only users in group X are able to see and/or edit the groups in that category.
and the same with group2, category 2, etc.
This is repeating by hand, keeping control of all datails, of what Mod AulaWiki does automatically, but workspaces are for advanced admins. If y ou are a newbie, just start doing things by hand, until you master how Tiki handles objects, permissions, categories, etc.
and Welcome to TikiWiki Community!
P.S. where are you from?