I understand that you want to bind a keyboard combination to the menu item "Tools > Locate > Artist", using the MC Standard View interface.
I will assume that the workflow or use case you have for this would be;
Search or browse aroound in MC for something to play.
Locate an Artist you want to hear more of.
Hit a key combination that runs the "Tools > Locate > Artist" function.
With the display now showing only tracks from that Artist, select new music to play.
There are a few difficulties with that. The main one is that the Key Combination would need to have as input the currently selected Artist. That works easily when using the menu function, and would work fine with an MCC Command if one existed for that menu function. But it appears that there isn't such an MCC Command, so an MCWS command needs to be used, and I don't think the currently selected Artist is available to MCWS commands unless there is a program running that first asks for the current Artist with one MCWS command, and then uses that information to send the equivalent of the "Tools > Locate > Artist" function using the already determined current Artist. I could be wrong on this, but as MCWS commands could be issued from any device on the network, I don't think they can use, for example, the notation of [Artist] in HTTP commands.
Sorry to get a little technical.
I asked about whether you use a mouse, because with "Options > General > Features > Linkable Columns" selected, there will be a small arrow to the left of the contents of various columns in MC Standard View, and when you click such an arrow next to an Artist's name, MC will filter the View down to just that Artist. In other words, it does exactly what you are asking for. Exactly the same as selecting the menu item "Tools > Locate > Artist".
So, that is an alternative to creating a key bind for that menu function.
If you wish to pursue creating a key bind, you will need to;
- Create a "Custom Resources" folder in "C:\Program Files\J River\Media Center 25\Data". See https://wiki.jriver.com/index.php/User_Defined_Global_Keyboard_Shortcuts
- Create a "Resource.xml" in that folder, similar to the Resource.xml in "C:\Program Files\J River\Media Center 25\Data\Default Resources". The Resource.xml is sort of self-documenting, so you can look at the original to work out what to put in the customised version. You only need to put additional customisations into the new file. MC will use both Resource.xml files to determine all key binds it uses. Leave the original Resource.xml untouched, as it may be overwritten in future MC updates. You can just copy the original Resource.xml into the new "Custom Resources" folder and edit it if you wish.
- Select a Key Combination that isn't being used as a Global Keyboard Shortcut by Windows or other application software, or in the original Resource.xml by MC. (Okay, you can override other application and Windows Global Keyboard Shortcuts, but that just complicates things if MC isn't in focus on the PC.)
- Work out what command to bind to the key combination you set.
How to determine the current Artist.
If it is available using the [Artist] field, what command to use it in. I don't see a standard MCC Command that will work. That would be the best solution though. https://wiki.jriver.com/index.php/Media_Center_Core_Commands
If an MCC Command isn't available, use the MCWS command discussed above, and somehow pass the "Artist" name to the command.
Sorry, that is all I have. I can't give you an easy solution, other than the Linkable Columns mentioned above.