You can enter multiple search values separated by a comma when you build a rule. First you select a new search field and choose the "contains" comparison. Then enter multiple values separated by commas.
Turn on the "Split up fields with commas" option in the rule settings. When you want multiple values split by commas, the values will use the "or" comparison for each item.

When you enter values for date fields, you can add multiple types of date values. The empty date field will show you the date format examples. You can enter a date using the date format for your device settings. eg. Date/Month/Year or Month/Date/Year. Use numbers for the month value.
You can also add age date values such as yesterday, days, weeks, months or years. This will compare the search field with the number of days (etc.) before the current time. This is useful for deleting emails older than 2 weeks. You could also move emails to another folder after 2 months. Examples are: 2 days, 3 weeks, 5 months, 2 years. You can also combine values like "2 months 1 day".