At the top of the Proposal Page is the filter option -

There is the option to filter by New Business, Renewal, MTA or all and the other option is by Broker.

The default setting will be All Policies

The Broker option will give you the names of all those on your system, just your own or everyones.

Nothing ticked in the drop down will result in "None Selected"

Tick the type of policy required

This will result in only MTAs being shown in all sections of the Proposal Page