You can change the display name of the filter value by using the following steps:
Go to your Shopify Admin Store > App > Searchly.
Click on Filters and select Manage Filters.
Click On the Symbol in Action Field.
Then it will re direct to Manage Filter and Manage Filter Values page.
Select Manage Filter Values field.
Select a filter whose values you want to rename and click Manage Values (Product Tags in this case).
Change the name of the value by changing it under the Display Name column and click the Save button e.g (Wheels and Covers => Wheel Covers)
Run data sync by clicking Data Sync.
Please see this example for reference:
Filter value without name changed:
Filter value with the name changed: