Hi,
Refer below node which displays the option in nav only if the user has read access to /etc/workflow/models
/libs/wcm/core/content/sites/jcr:content/actions/selection/create/items/createworkflow/granite:rendercondition
/libs/cq/gui/components/renderconditions/canreadworkflowmodels/canreadworkflowmodels.jsp
Hope this helps