Yeah its quite easy.

Just customize your usertable and add new enum field called GroupPermissions and add these to it

group1 group2 group3

and then you can modify your templates ie search results to add something like

<%if GroupPermissions eq group1%>
Show this to group1
<%endif%>

<%if GroupPermissions eq group2%>
Show this to group1
<%endif%>

<%if GroupPermissions eq group2 or GroupPermissions eq group3%>
Show this to group2 and group3
<%endif%>

Something like that