OnePage layout – Menu links

Hi there fellow customizrs!

I managed to create a single page like in this snippet

Let’s say i’ve got PageA containing PageB, PageC e PageD:

How can i make the Menu link to the contents shown in PageA, instead of linking directly to B, C or D?

On a normal page i would use #id-of-the-element-of-the-page but here it’s more tricky…