Use this filter in your child theme to overwrite/extend the CSS selectors the “Theme Style > Link” settings are applied to like this:
add_filter( 'bricks/link_css_selectors', function( $link_css_selectors ) {
// Add CSS link styles to .my-custom-element a
$link_css_selectors[] = '.my-custom-element a';
// OR return new list of CSS link selectors
// $link_css_selectors = ['.link-wrapper a', '.link-wrapper-2 a'];
return $link_css_selectors; // Array of selectors link styles are applied to
} );