Steps to reproduce the issue

Consider the following form

      <fieldset name="settings" label="LABEL">
        <fields name="fruites">
            <fields name="apple">
                <field name="enabled" type="radio" 
                    label="JENABLED" 
                    default="1">
                    <option value="1">JYES</option>
                    <option value="0">JNO</option>
                </field>
                <field name="price" type="text" 
                    showon="enabled:1" 
                    label="label1"
                />
            </fields>
        </fields>
    </fieldset>

Expected result

The price should be shown when we choose Yes on the enabled field

Actual result

The price field never shows up

System information (as much as possible)

Joomla! 3.7.0-beta2
PHP 7.0.15

Additional comments

Here's the produced showon attribute on Joomla 3.7.0-beta2
data-showon='[{"field":"jform[fruites.apple][enabled]","values":["1"],"sign":"=","op":""}]'

And here's the produced showon attribute on Joomla 3.6.5 which works
data-showon='[{"field":"jform[fruites][apple][enabled]","values":["1"],"op":""}]'