Get entered data from fields for shortcode

This is very rough and meant as more an illustration of how, not a final implementation.

function barfoo( $object_id, $this ){
    $one = get_post_meta( $object_id, 'foo_text', true );
    $two = get_post_meta( $object_id, 'foo_textdate', true );
    $thr = get_post_meta( $object_id, 'foo_text_two', true );

    if ( ! empty( $one ) && ! empty( $two ) && ! empty( $thr ) ) {
        echo '[event-button name="' . $one . '" date="' . $two . '" price="' . $thr . '"]';
    }
}
add_action( "cmb2_before_post_form_02_test", 'barfoo' );

It uses this hook:

do_action( "cmb2_before_{$object_type}_form_{$this->cmb_id}", $object_id, $this );

The 02_test part comes from the ID my local install has for the id param in new_cmb2_box(). Allows you to specify the output for only specific metaboxes. Wrapped the output in the if statement in case you don’t have all the fields. Possible to also do it just for available/provided fields.

Customize as you see fit.

Thanks Michael this helped a lot. I currently have this working and looping through a saved group. However, it would be nice to display each separate shortcode above the first repeatable field in a group. Is there any hook to repeat this inside a group?

Not seeing any for after each group, to be honest. I have to wager due to the nature of how repeated groups are appended, not doing a hook there was considered not worth it.