Cross platform please

Please give cross platform I have 2 brothers which both have pc and we have a Xbox one and we really want to play together so if you could do cross platform please that will be great what you could do is when your in a party or group with friends that are on different platforms you go cross play but when alone with no one on a different platform there’s no cross play but if you cant do this I understand also I put it on technical support because I can only chose between bug reports and technical support