plugins/CustomVariables/templates/_actionTooltip.twig

{% if action.customVariables is defined %}

    {{ 'CustomVariables_CustomVariables'|translate }}:{% for id,customVariable in action.customVariables %}
        {% set name = 'customVariablePageName' ~ id %}
        {% set value = 'customVariablePageValue' ~ id %}

        {# line break above is important #}
        - {{ customVariable[name]|rawSafeDecoded }} {% if customVariable[value]|length > 0 %} = {{ customVariable[value]|rawSafeDecoded }}{% endif %}
    {% endfor %}
{% endif -%}