You can create a parameter for the client selection. (Add from field Customer Name)
And create the following filter and keep the true value.
[Customer Name] = [Select Customer] or [Top Customers by Profit]
You can keep the Top Customer set on the Rows at the left and hide it , if you want to keep the selected patient below the top N.
The only drawback, is if new customers are added to the dataset you will have to manually repopulate the parameter.
If this is not an option, you can always put two sheets in a dashboard, one for the Top N and one for the selected customer.
Top N vs Client(mc).twbx 396.5 KB
Don't do the sets.
In the attached I made a RANK calc to rank profits. (See [Rank Profits].)
Using that calc, I made another calc to display profits only for the top 5 customers. See [Top 5 Profits].
I have it on the sheet in two places -- in the measure values list, and on the details shelf. The one on the details shelf I changed to DISCRETER (blue pill.) Drag it to the front of the list on the ROWS shelf to see tableau sort the sheet by RANK.
Top N vs Client_v2018.1.twbx 361.1 KB