By looking at the drone picture from this article [1], it seems that the east side has 2 entrances, one going north (and seems lightly curved towards the right when going to Jezus Eik) and one going south that is currently un-mapped.
However, as this picture is the only source i have, i don't dare map it myself. If i find some time, i'll try to survey it.

[1] https://www.dhnet.be/regions/bruxelles/bruxelles-mobilite/2023/06/28/apres-un-long-chantier-le-tunnel-cyclable-sous-le-ring-de-bruxelles-a-overijse-enfin-ouvert-SSN253A3YFGYTHGJFYFD75HLXU/

The parking surface as well as the "garden" of the Pépinière have been severely diminished by a new construction. The construction is not finished but it will at least remove the access to the Parking from the roundabout