Yes, there is, at least I’ve used a repeater field in a new field type https://github.com/Hube2/acf-medium-editor, it actually includes a nested repeater. (see line 248 of https://github.com/Hube2/acf-medium-editor/blob/master/fields/acf-medium-editor-v5.php)
Basically, any field type can be used as a field setting for another field type. For example, all of the “text” setting fields are ACF text fields. Same goes for every other field setting that you see.
The main difference that I found is that with repeater sub fields is that you need to set the “key” attibute to the same value as the “name” attribute. This will be what ACF uses to store your sub field value internally.
