Add a button (link) for each member in the member directory, and also add a button (link) to the user profile.

um_custom_button_in_profile.php

<?php

/**
 * Change the $href variable to an URL that navigates to a page you need 
 * and change the $title variable to a button text you need 
 * then add this code to the functions.php file in the theme directory.
 */

// Add a custom button (link) on user profile.
function um_custom_button_in_profile( $args ) {
	$href  = home_url( '' );
	$title = 'Custom form';
	?>
	<div class="um-profile-custom-btn">
		<a href="<?php echo esc_attr( $href ); ?>" class="um-custom-btn um-button"><?php echo esc_html( $title ); ?></a>
	</div>
	<?php
}
add_action( 'um_profile_navbar', 'um_custom_button_in_profile', 4 );

// Add a custom button (link) for each member on member directory.
function um_custom_button_in_member_directory( $args ) {
	$href  = home_url( '' );
	$title = 'Custom form';
	?>
	<div class="um-members-custom-btn">
		<a href="<?php echo esc_attr( $href ); ?>" class="um-custom-btn um-button"><?php echo esc_html( $title ); ?></a>
	</div>
	<?php
}
add_action( 'um_members_just_after_name_tmpl', 'um_custom_button_in_member_directory', 110, 1 ); // for grid.
add_action( 'um_members_list_just_after_actions_tmpl', 'um_custom_button_in_member_directory', 110, 1 ); // for list.

// Style a custom button.
function um_custom_button_styles() {
	?>
		<style type="text/css">
			.um-profile .um-profile-custom-btn {
				float: right;
				margin: 0px 0px 0px 5px;
			}
			.um-profile a.um-custom-btn {
				padding: 10px 15px !important;
			}

			.um-members.um-members-grid a.um-custom-btn {
				display: inline-block !important;
				font-size: 13px;
				margin: 0 auto !important;
				min-width: 110px;
				padding: 10px 15px !important;
				text-align: center;
				transition: none !important;
				width: auto;
			}
			.um-members.um-members-list a.um-custom-btn {
				font-size: 13px;
				padding: 10px 15px !important;
			}
		</style>
	<?php
}
add_action( 'wp_footer', 'um_custom_button_styles' );