Könnten Sie mein Gepäck bitte herunterbringen lassen?
How does usage of lassen work here?
Can anybody please give more examples of lassen similar to this one.
Normally it means leave.
dict.cc gives to have sth done as the second but last translation.
This exactly reflects the usage of lassen in this context.
The translation of your example would be as follows:
Could you please have my luggage brought down (to the entrance hall)?
one could also translate using to let:
Could you please let the luggage be brought down?
Lassen Sie den Wagen vorfahren.
Lassen Sie das Essen bringen.
Könnten Sie bitte den Champagner auf das Zimmer bringen lassen?
In this context "lassen" will be used with an action of a third party. The first party is the "requester". He asks the second party, the "middleman" to give the third party, the "requested", instructions on something to be done in a certain way. Sometimes second and third party are the same person, but that is rather unusual.
You might hear this construction in a 5 stars hotel, like 'Ritz', when a guest asks the concierge for something to be done.