Have a colleague request, I’ll be looking into.
Does something like this have to be scripted?
They’re having a hard time differentiating between curves that share the same space, for example.
So, I’m wondering if it can be done with a script or something, maybe click of a button to help the user know what’s there to click on…
Hi
You can set curve type in layers. When one draws, draw your lines that share the same space in a different layer that way you can always select them by right click on the layer and selobjects option. Or after you draw them sellast then send to a different layer. I use different line types and colors to help differentiate.
If they’re already drawn…
And they are the same curves seldup should find them
If they are a certain length use selshortcrv and type in the length of line/s you are looking for. Sometimes one has to select group and or lock objects then use some of the methods like selshortcrv.
Use selcolor command if they have a unique color.
There are some scripts floating around mostly from Mitch helvetsaur search for seldup or selecting duplicates.
But it’s easy to solve if you just put curves on different layers. Not so easy if you’re getting the linework from a 3rd party.
RM
Indeed these are very good techniques. The problem however is with users who don’t know the curves are there in the first place, and when they go to select a long curve but then they pull up a shorter curve in the way, for example, they get frustrated and they want Rhino to automatically make it clear that there’ a shorter curve in the way. 
And/or if they want to find the shorter curve but they don’t know where to click on the longer curve in order to find it. 
So they want Rhino to automatically differentiate the shorter curves so they can see them easier with their eyes. 
They’d like the “shoter one to show up differently, like darker or somehing” 
Similar to when two surfaces share the same space, they show up differently and you can tell visually that they share that space.
But with curves it’s very much hard to tell when they share the same space.
They’d like Rhino to visually automatically indicate where curves are sharing the same space. 
Hi,
And even worse when there are surfaces there as well and items are grouped or locked, selection filter helps there but despite Rhinos extensive selection commands it still could use these things.
That’s why first turning on and off layers is a good start when looking at any outside file.
I could only suggest a few tedious work arounds.
I too get frustrated selecting things many times but one has to at least know how to organize since Rhino is limited to some extent in this area. I don’t think many cad programs do a good job when it comes to this problem. Those are nice wishes and would be great if Rhino could do them. Imagine some programs don’t let you select objects in the viewport and you have to select them in a drop down list talk about tedious or life gets tedious don’t it.
RM