This will split it and remove whitespace:

    String initialString = 'Malcolm Bell Landgraab | EMP-00012 | Consultant';
    String[] results = New String[]{};
    
    for(String val : initialString.split('\\|'))
        results.add(val.trim());
    
    system.debug(results);

I am pretty sure this will also remove the whitespace before and after the separator without having to use trim or the loop

    String initialString = 'Malcolm Bell Landgraab | EMP-00012 | Consultant';
    String[] results = initialString.split('\\s*\\|\\s*');
    system.debug(results);