This is the 191st most frequent Finnish word.
oleva
"Existing" or "being."
This usage demonstrates 'olevan' (having the same root as 'oleva') in an infinitive form to express a necessity or attribute in an indirect statement.
Hän huomasi olevan tärkeää kunnioittaa muita.
He noticed that it is important to respect others.
Here, 'olevat' indicates those who are currently in a certain condition or state, referring to 'employees' who are present.
Siellä oli paljon ihmisiä, mukaan lukien olevat työntekijät.
There were many people there, including the employees present.
'Oleva' in this case is an adjective describing an ongoing or present situation.