I assume that you're talking about the behavior of 'QuickPick'. And actually, NO, there is no way to change it back since it was technically not working correctly and I think if you'll follow along here and try it yourself, you'll see what I mean.
To start with, in NX 3 and prior releases, the behavior of selecting say a feature was inconsistent depending on whether you were selecting from the Screen/Part Navigator or using 'QuickPick', and we should have caught this when we first implemented QuickPick, but for whatever reason we didn't which was our mistake. When selecting from the Screen or from the Part Navigator the action is to either double-click with MB1 (Left Button), or single select with MB1 and then use MB3 to select the desired actions, such as edit. And if after a single MB1 select, you were to press MB2, it would have then pre-selected the NEXT object within the pick area. Now this interactive behavior has NOT changed in at least 20 years or so and continues to the latest releases of NX and no one has ever suggested that we make any changes when NOT using QuickPick. Are we agreed on this?
However, the problem with NX 3 and prior releases, is that when using QuickPick the user interaction was pressing MB1 triggered the QuickPick 'list' but pressing MB1 the second time moved the pre-selection to the next item where you had to press MB2 to actually make the selection, which was completely opposite of what it was when NOT using QuickPick:
No QuickPick - MB1: Select Item - MB2: Highlight Next Item
With QuickPick - MB1: Highlight Next Item - MB2: Select Item
So starting with NX 4 we changed both the appearance, and behavior of QuickPick. In addition to adding the filtering options (since starting in NX 4 we also did away with Selection 'Modes' and went with Selection 'Priorities'), we also changed the behavior of depending on which mouse button you used next. So now pressing MB1 triggered QuickPick and pressing it again performed the selection, as a sort of 'slow-motion' double-click, while MB2 moves the pre-selection to the next item, which is again consistent with the on-screen interaction:
No QuickPick - MB1: Select Item - MB2: Highlight Next Item
With QuickPick - MB1: Select Item - MB2: Highlight Next Item
And if that was not enough of a reason to switch the MB1/MB2 behavior, once the QuickPick was an actual 'list', we could now use a wheel-equipped mouse to move up and down the list and since generally speaking, the 'wheel' is also MB2, this only makes sense to have a single push of MB2 advance the list highlight whereas using the MB2 'wheel' would perform a dynamical advance the highlighting of items.
So if you were to start using NX 4 and then were to use NX 3, your first impression would be that QuickPick was backward. It would be so obvious you would wonder why it had ever been implemented in that manner in the first place. There would be a 100% consensus that it was a 'bug', and therefore why would anyone want to go back to what is now so obvious a mistaken implementation. Granted, we should have caught this years ago and made the changes then, but...
John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Cypress, CA
To an Engineer, the glass is twice as big as it needs to be.