You can use
[rwmb_meta]shortcode built in Meta Box plugin to deal with the problem of inserting values of custom fields in post content without opening theme files and inserting PHP code.
The shortcode take the following attributes:
[rwmb_meta post_id="15" meta_key="field_id" type="image" size="thumbnail" ...]
[rwmb_meta] shortcode works exactly like
rwmb_meta function (look at this documentation). All attributes are the same.
|The post ID. Optional. If not defined, then the ID of current post is used.|
|The meta key, same as field ID. Required.|
|Field type. Default is |
|If field has multiple values (like |
|Image size, used for image fields only. If not present, the |
|The taxonomy for which to retrieve terms, used for taxonomy fields.|