You can have a column called Other Condition in the decision table where you can specify a full blown condition (including nested AND and OR conditions).
Locate the ruleset (Where is my ruleset?) and double-click the ruleset node.
In the Outline view, choose a decision table node.
In the decision table editor, choose the Condition button.
In the menu that appears, choose Add Other Condition.
Save the changes.
Note
You can also add an other condition when you create a decision table as follows:
On the Select the Conditions screen of the Decision Table Wizard select the Table has Other Condition checkbox.
To rename an other condition, in the decision table editor choose the Condition tab and use the Rename Other Condition option.
To add a condition, double-click a cell under the Other Condition header in the decision table.
In the editor that appears, choose the icon that looks like a plus icon.
The default condition: System.currentTimeMillis() Greater Than 1208497381741 appears.
To edit the default condition:
Choose the LHS value:System.currentTimeMillis() and in the drop down menu choose a definition or alias.
Choose the comparator: Greater than and choose a comparator in the drop down menu.
More Information: List of Return Types and Comparator Choices for Conditions
Choose the RHS value after the comparator and in the drop down menu choose a definition or alias.
Press Alt + Enter and save the changes.
Note
To add nested conditions, repeat the steps and add more conditions. The conditions appear within parentheses and are combined by the logical operator: and. You can change the logical operator by clicking it.