I'd suggest the following:
Create a parameter and populate it with all of the names.
Remove the filter and place Name on the detail card. This will create a line for each person.
Create a calculated field that will allow you to highlight the person you select. Something like:
IF [Name] = [Selected Name] THEN
Then drag that to the color card. Set Grey to a grey shade and Color to some other shade such as Red. Once you do this, you'll have a bunch of grey lines for the other people and a red line for the person you select. So you'll be able to highlight the selected person while comparing to peers.
Here's an example using superstore.
I've attached the example.
Parameter Highlight.twbx 2.4 MB
In order to compare one person's performance to that of the others, I would create a group that is comprised of all the people not chosen for comparison. This will give you the average performance of everyone other than Amy or whomever else you choose for comparison. Then you just need to put the person chosen in a parameter and the group in detail to have two lines. You can color them differently if this helps the visualization.