README.md

Usage:

• Add the mixin somewhere
• Duplicate the mixin instructions into your require-js
• Form XML:

  <form xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
      <!-- ... -->
      <field ...>
        <item name="config" xsi:type="array">
          <!-- ... -->
          <item name="fieldDependency" xsi:type="string">${ $.provider}:${ $.parentScope }.FIELD_TO_DEPEND_ON</item>
        </item>
      </field>
    </form>

Where FIELD_TO_DEPEND_ON is the name (in the current scope) of the field you want this to only be visible if it has a truthy value.

field-dependency.js

define([], function() {
   'use strict';

   return function(targetModule) {
       return targetModule.extend({
           initialize: function() {
               this._super();

               if (this.fieldDependency) {
                   this.initFieldDependency();
               }
           },

           initFieldDependency: function() {
               // Initial setting
               var dependency = this.fieldDependency;
               this._changeDependencyValue(this.default);

               //
               this.setLinks({
                   '_changeDependencyValue': dependency
               }, 'imports');
           },

           _changeDependencyValue: function (value) {
               var show = !!value;
               this.visible(show);
           }
       })
   }
});

requirejs-config.js

var config = {
    'config': {
        'mixins': {
            'Magento_Ui/js/form/element/abstract': {
                'Briteskies_Organizations/field-dependency': true
            }
        }
    }
};