In Options > Theatre View > "Items to show" for the Video/Shows/Series group, select "Set rules for file display..." under the Details heading, then add a rule to "Modify Results" of "Sort by: Date Recoded (a-z)".
This is a different setting to the "Set rules for file display..." at the Video/Shows group level, which you use to select what is included in the view overall normally. It is also different to the sorting applied to a Detail group such as the Season group under Video/Shows/Series. For example, I sort the Seasons within each Series in Descending order rather than Ascending order, so that the most recent Season is always the first Season in the display. For Series with a lot of Seasons, such as "The Simpsons" in my example, that means no scrolling to the latest shows if I am watching the current Season.
In the first image below you will see I have a group called Video/Recorded TV/Series, and I have left in the Details for that group both Series and Season, so in my example I am sorting by Date Recorded (a-z) within each Season. However, if I just remove the Season Detail group, the result is that all recordings within the Series are sorted by Date Recorded, in ascending order. I tried that and it was just one big list, which I could see was out of order because I have Season and Episode numbers on my recordings, and those numbers are shown at the left of the Episode name. But if you had no Season and Episode numbers, and the recordings were made in the correct sequence, I could see that such a view would be useful. Of course you wouldn't know if you were about to watch them out of sequence if the broadcaster transmitted them out of sequence. In Australia that happens quite often, although mostly the current Season is on one channel, usually their HD channel, and repeats are on another channel, usually the SD channel, so view that sorts by [Artist] (which is the broadcasting channel) and then by Date Recorded may separate them. But then just as often a broadcaster transmits a current Episode immediately followed by an old Episode, so that view wouldn't separate those Episodes. Trying to make all that work could get very messy though, which is why I try to get Series, Season, and Episode data for all programs into my EPG using "EPG Collector" and its metadata lookups, before a program is recorded. Sometimes difficult, but much easier in the long run.
In the second image you can see the result of adding the Modifier to sort recordings, where Episodes in Season 26 are no longer sorted by Episode number, but are sorted in ascending order by Date Recorded.
