Views Or: Begin alternatives =
Taxonomy: Term ID = Carrot
Views Or: Next alternative =
Taxonomy: Term ID = Elephant
Views Or: End alternatives =

how can i allow to user to select which combination to use right now?

for example, i want to create a view with filter:

Show all nodes
Show all nodes authored by ADMIN role
Show all nodes NOT authored by ADMIN role.

how can i do it?

thanks.