You didn't explain why Splunk does not give you SubID automatically. The illustrated logs are conformant JSON. If they are the raw events, there should be no reason that you don't have both fields submitterType and SubID.
If the illustrated log is one of fields that Splunk extracts for you, say "log", spath is the command to extract JSON nodes.
| spath input=log
Your sample data will give
SubID | submitterType |
App_4-45887-02232023 | Others |
App_5-45892-02232023 | Others |
You don't say much about what you need other than the results of that field, so in its basic form, you need to extract that SubID field if it's not already extracted and then do
your_search...
| table SubID
If your data is JSON then SubID should be extracted
If you want to count the occurrrences of each SubID, then do
your_search...
| stats count by SubID
Just trying to extract the field.