If someone handed me something as badly worded as that I’d be asking them very politely to take it away and sort it out.
Take the layout away and read the text sequentially it could break in a number of places but this is really the only one that seems to work to my mind.
Disabled badge holders only Mon-Fri 8am – 6pm
This is very clear during that time the disabled badge restrictions apply
3 hours at any other time
this second bit needs to belong to something and since there’s no earlier restrictions on length of stay it has to either mean:
Disabled badge holders can only park for 3 hours outside the working day – that seems an odd rule to me without some specific factor to drive a need for that restriction.
OR
Demand for disabled spaces is lower at that time and the intention is others can then make use of the spaces but not for more than 3 hours.
Even that seems a bit odd unless it’s trying to prevent overnight parking. IMO the second one is the right one.