How to change the label of exposed grouped Filter field in Views?
Normally you can remove field machine name from the configuration itself as shown below, but seems like those portion is hidden from your screenshot. Please check those portion, also check this troubleshoot Can't set the label for an exposed grouped filter.

If still no help you can use hook_form_alter(&amp;$form, &amp;$form_state, $form_id) to change the label