Hi @crazyguy ,
Could you please share a bit more about your issue?
Do you want to list all available Security Roles for a specific team?
I have made a test on my side, and don't have the issue that you mentioned. The screenshot as below:


Add two Galleries in your app, set the Items property of the first Gallery to following:
Teams
set the Items property of the second Gallery to following:
Gallery1.Selected.'Security Roles'
Please make sure you have configured proper Security Roles for the specific team in your Org. Please consider go to your Power Platform Admin Center, then click Environments tab, find your current Environment, then click "Settings" option, then expand the "Users + permissions" option, then click "Teams" option:

then within the opening Teams record page, switch View option to "All Owner Teams", then select specific team, then click "Manage Roles" option in Top Menus:

then check if you have assigned Security Roles for the selected team.
Best regards,