Cypress - have to use forEach loop with array returned by function in describe block

I have a function which returns array

 getOffersCategories() {
    cy.get(offersHeaders).then($els => {      
      cy.wrap(Cypress._.map(Cypress.$.makeArray($els), 'innerText')).as("categories")
    })
    return this;
  }

Now I need to call this function and use array with forEach block having multiple test cases (something like this)

offersCategories.forEach((item, index) => {
        it("Validate Max Carousels Limit, Left Right Swipe, See All link of " + item, function () 
        {
          ...
        }
})

For me it works fine if I array value is declared in same spec file Like var offersCategories = ["a", "b",c"] or fetched from fixtures, but not finding any way to use the same functionality when array details fetched from function.

Thanks in advance :)