Not sure what you mean exactly, but you can do the following.  “Alexa play xxxx from Spotify in the Lounge” Assuming the Play 5’s are set as lounge in rooms and they are the default speaker in the Alexa groups for that room.  There are other combinations of solutions too, such as grouping the One and Play 5’s and lowering the volume of the one.

However.  I have found it easier to have a cheap Amazon Alexa dot to do this rather than a Play one.  You could buy one and have it in the room with the Play 5’s to control them and have the One in another room as an Alexa device and speaker.  Hope that makes sense.