ruby noob here, any way
"ManagerID='26a20e0e-23ba-4133-8bf4-e56f13115902' OR
ManagerID='c86eede4-fdb4-45a8-88cf-4041c9d7a327'".gsub(" OR ",'')
would produce =>"ManagerID='26a20e0e-23ba-4133-8bf4-e56f13115902' ManagerID='c86eede4-fdb4-45a8-88cf-4041c9d7a327'"
then split it by ManagerID=
"ManagerID='26a20e0e-23ba-4133-8bf4-e56f13115902'
ManagerID='c86eede4-fdb4-45a8-88cf-4041c9d7a327'".split("ManagerID=")
would produce => ['26a20e0e-23ba-4133-8bf4-e56f13115902', '26a20e0e-23ba-4133-8bf4-e56f13115902']
then simply join them by coma
['26a20e0e-23ba-4133-8bf4-e56f13115902', '26a20e0e-23ba-4133-8bf4-e56f13115902'].join(',')
this should give you the expected result, basically you can chain these operations into one statement, if my knowledge is correct, below code would give you the result.
"ManagerID='26a20e0e-23ba-4133-8bf4-e56f13115902' OR ManagerID='c86eede4-fdb4-45a8-88cf-4041c9d7a327'".gsub(" OR ",'').split("ManagerID=").join(',')
str.scan(/(?<=ManagerID=').*?(?=')/)