UserMeta

$meta_query = array(
	'relation' => 'AND',
	array(
		'relation' => 'OR',
		array(
			'key'     => 'wtba_relationship',
			'value'   => 'associate, contractor',
			'compare' => 'IN',
		),
	),
	array(
		'relation' => 'OR',
		array(
			'key'     => 'wtba_contact_type',
			'value'   => 's:4:"main";s:3:"Yes"',
			'compare' => 'LIKE',
		),
		array(
			'key'     => 'wtba_contact_type',
			'value'   => 's:4:"main";s:2:"on"',
			'compare' => 'LIKE',
		),
	),
);