Dashboard list how to get a distinct list from a distinct list with Arcade?

[ThomasColson]

I'm trying to build a dashboard list from a feature class that is a lot of polylines, something like this:

• Trail 1, State 1, District 1
• Trail 1, State 1, District 1
• Trail 1, State 1, District 2
• Trail 2, State 2, District 3
• Trail 2, State 2, District 4
• Trail 3, State 3, District 5
• Trail 3, State 4, District 6
• Trail 3, State 5, District 7
• Trail 3, State 6, District 8
• Trail 3, State 7, District 9

What I want the list to show is: 

• Trail 1, 1 State(s), 2 District(s)
• Trail 2, 1 State(s), 2 District(s)
• Trail 3, 5 State(s), 5 District(s)

What I've got so far is: 

var fs = FeatureSetByPortalItem(Portal('https://arcgis.com/'), 'a454cf97c4264cd2b77f27175e01d3ba', 0, ['TRLNAME','STATE','CONG_DIST'], false);

return GroupBy(fs, ['TRLNAME'], 
[{name: 'total_states', expression: 'STATE', statistic: 'COUNT' }, 
 {name: 'total_districts', expression: 'CONG_DIST', statistic: 'Count' }]); 

 Which gives me

Which is giving me unique trails, but very clearly not the unique state, district for each trail. 

How do I narrow down the expression to return unique states,districts for each trail? Not a programmer.....