Since the soundbar is going to do your audio the BD receiver is only going to be used as a disc player. The problem is that it may not send audio through the HDMI output that would connect to the TV. You can try it and see if you get sound from the TV speakers.
If you do then just connect the soundbar to the TV optical audio out.
If not then then there are ways around this but it makes more sense to buy an inexpensive BD player. If you go this way connect the cable box and disc player to the TV with HDMI. Connect the soundbar to the TV with optical audio.
If you have to use the receiver then you could connect the cable box to the receiver with HDMI and the receiver output to the TV with HDMI. You would need an adapter like this...