There will be times when the same activity is performed by multiple roleplayers at the same time and you need to depict this in a standard UML activity diagram or a BPMN diagram. The way to represent this is to depict the same activity multiple times across swimlanes as shown below.
Same activity in multiple swimlanes
UML 2.0 doesn’t explicitly state that you shouldn’t place an activity between two swimlanes which is something people do when the same activity is done by two roles but obviously you can’t do this for three roles.
However, the BPMN spec explicitly prohibits you from keeping an activity across swimlanes. At times, people get into a philosophical argument on whether the same activity is really being done by two roles. For instance, in this example, although the activity might be reviewing requirements, you may argue that the technical lead reviews it from a technical perspective while the product owner reviews it from a business perspective.
Personally, I don’t buy this argument; at the end of the day they are reviewing requirements and nothing prevents the technical lead to give business inputs and vice-versa. In practice, the activity itself is also likely to be called a review and not a review from a technical perspective or a review from a business perspective. So, in order to reflect reality, and not get into a web of semantics I recommend that you call the activity the same name, and show it multiple times across swimlanes.