use code like this

        MenuItem searchItem = menu.findItem(R.id.action_search);
        SearchView filterPartsSearchView = (SearchView) searchItem.getActionView();

        if (searchManager != null) {
            filterPartsSearchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
        }

       filterPartsSearchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
        filterPartsSearchView.setBackgroundColor(ResourcesCompat.getColor(getResources(), android.R.color.transparent, null));
 
        View searchPlate = filterPartsSearchView.findViewById(androidx.appcompat.R.id.search_plate);
        if (searchPlate != null) {
            searchPlate.setBackgroundColor(Color.TRANSPARENT);
        }

This is Ref Image of selected text

2nd image Ref when cursor pressed and hold for highlight text while move cursor around text