So, a couple of things.
(1) You can only get help for a cmdlet if the cmdlet is installed on whatever computer you’re asking for help on. If you’re remote into a computer, that computer needs the command installed. PowerShell won’t look on your local machine for help files if you’re remoting into a machine.
(2) Not every product installs help along with commands. You may need to run Update-Help on whatever computer contains the commands.
(3) If a command is installed, but not the help, you’ll still get an automatically-constructed help file, but it won’t include examples, or detailed descriptions.
Your original thread was “why doesn’t the help work,” which is what I was trying to answer. However, reading https://technet.microsoft.com/en-us/library/dd298173(v=exchg.150).aspx (which is the same as the help for the command would be), the -SearchQuery parameter indeed seems to accept multiple OR values; see Example 4.
https://technet.microsoft.com/en-us/library/dd298064(v=exchg.150).aspx indicates that -SearchQuery accepts a KQL query; https://msdn.microsoft.com/en-us/library/office/ee558911.aspx provides a KQL reference.
I tend to find the web-based help more accessible and more up-to-date, and often use that in preference to the local help. It’s also a bit easier for me to float it around in a separate window, resize the text, quickly jump to cross-references, that kind of thing.