exmpl.html

<!-- UserForm.vue -->
<user-form>
  <field-1 />
  <field-2 />
  <field-3 />
</user-form>

<!-- DialogUser.vue -->
<common-dialog>
  <template scope="form">
    <slot />
  </template>
</common-dialog>

<!-- On page -->
<dialog-user>
  <user-form>
</dialog-user>