portfolio icon/thumbnail leads back to nowhere

I set up my portfolio page as: /les-outils.
When I am on one of four my “portfolio” subpages (for example: https://leadingdynamicstability.com/portfolio/mobiliser-les-energies-vers-le-changement/), the icon/thumbnail in right upper corner leads me to:
https://leadingdynamicstability.com/portfolio/
but this site doesn’t exist.
It should lead to: https://leadingdynamicstability.com/les-outils/.

How to:
1-either change address of my 4 subpages of portfolio (so they don’t have “portfolio”
2-or put the correct hiperlink under this icon?