Session Group: Recently Accessed the last x (hours, days, ...) from Support employee

The Scenario:

We have a increased number of colleagues, who are using access sessions within our corporate network.

Those support employee´s are connecting regulary to the same machines.

So I tried to extend the filter similar to a build in one: Recently Accessed the filter looks like: "LastHostConnectedEventTime > $1DAYSAGO"

But those filter show all clients to all support employee´s, which has been accessed whin the choosen timeframe.

Improvement: The filter should only show Clients which have been accessed from an employee itself - NOT All.

Right now I have Similar Access Group in place, which displays devices, where the support employee is Logged on.

Filter looks like: 

(GuestLoggedOnUserName = (SUBSTRING($USERLOGINNAME,1,(LEN($USERLOGINNAME) - 14)))) OR
((SUBSTRING(GuestLoggedOnUserName,2,8) = SUBSTRING((SUBSTRING($USERLOGINNAME,1,(LEN($USERLOGINNAME) - 14))),2,8)) AND SUBSTRING(GuestLoggedOnUserName,2,1) IN ('0','1','2','3','4','5','6','7','8','9')) OR
((SUBSTRING(GuestLoggedOnUserName,4,6) = (SUBSTRING($USERLOGINNAME,1,(LEN($USERLOGINNAME) - 14)))) AND SUBSTRING(GuestLoggedOnUserName,1,3) IN ('Administrator','System'))