There are no bitwise shifts operators (or functions) in LibreOffice BASIC. I believe it would be highly beneficial if they were to be implemented. Of course, I am talking about the equivalent to the C/C++ operators << and >>. Also note that bitwise shift functions exist in Calc (BITLSHIFT, BITRSHIFT), however, for some strange reason, there's no such functionality in BASIC.
Just for information: MS Office's VBA doesn't support those either. Here is a workaround: http://www.excely.com/excel-vba/bit-shifting-function.shtml
I guess you are right -> NEW
MS Virtual Basic has them, also using "<<" and ">>": https://docs.microsoft.com/en-us/dotnet/visual-basic/language-reference/operators/bit-shift-operators