With Zabbix 4.0.0 we lost functionality of  double boxes to select members of Hosts for Template -[ZBXNEXT-4152].

In large environment we missing overview for filtered list of hosts with template. Twin boxes was simple and usable way to manage members also with group filter for list.

Please return this functionality (first for Templates) as Manage members form, invoked with button in editing form or in new pageframe. In this way return this functionality for User groups members and other past places.