Is it possible to add new booking into an existing group reservation in eZee Absolute?

Yes, It's possible.

Path: Login into eZee Absolute >> Group >> Group Reservation >> Edit Group >> Room Operations >> Add transaction to this group >> Select Transaction >> Add to group.

Screenshot 1: (Group >> Group Reservation >>Edit Group)

Screenshot 2: (Add new guest to this group)

Screenshot 3: (Take reservation/Check-in)

Screenshot 4: (Transaction added into the group)

Related Question: 

• Is it possible to ADD an existing transaction/guest(In-House) into an existing group reservation?