Your question is a two-part question:
1) In Security > Security Groups > Select a specific security groups
Give access to Domains module (System Config > Platform Config > Domains)
(see 170802-00.jpg)
2) Then hide all the domains except for MAINTWIN
(see 170802-01.jpg)
You can see in this screenshot all the domains are hidden except for MAINTWIN
(see 170802-06.jpg)
#Maximo#AssetandFacilitiesManagement