How to move one bspline so is tangent to other two

Please advise on version being used.

If using MicroStation CONNECT Edition one option is to use 3D Constraints.

First you will need to 'Fix' the curves not to be moved, then Constrain the remaining curve to them.

This is exactly what I was looking for. The bad thing is, you can't move or rotate anymore the third bspline, looks like it's not only forced to be tangent to the other two, but also be kept without being rotated or touching the tangents in the same points. If you dig it, you can "move" the bspline out of the touch of the other two, but kind of it's still attached. You can move it back without being tangent, like crossed. It's all shown in this video:

This video shows that you can't rotate the bspline while being constrained to being tangent. You have to Remove All, rotate it, and constrain it back:

To move one element to make it tangent to other two that are constrained, you have to select Constraints > 3D > Tangent > select the element to be moved clicking on it 3 times > click 3 times on the elements which is constrained, so the first one will move to it. Repeat the process for the other side (click 3 times on element to be moved > click 3 times on constraint).

Here's a third video, where I can't get the bspline to make it tangent without rotating it. Making the first tangengy works fine, however for the second time it rotates it without my consent. Any idea why this happens and how can I fix it? This behaviour is so inconsistent:

This is exactly what I was looking for. The bad thing is, you can't move or rotate anymore the third bspline, looks like it's not only forced to be tangent to the other two, but also be kept without being rotated or touching the tangents in the same points. If you dig it, you can "move" the bspline out of the touch of the other two, but kind of it's still attached. You can move it back without being tangent, like crossed. It's all shown in this video:

This video shows that you can't rotate the bspline while being constrained to being tangent. You have to Remove All, rotate it, and constrain it back:

To move one element to make it tangent to other two that are constrained, you have to select Constraints > 3D > Tangent > select the element to be moved clicking on it 3 times > click 3 times on the elements which is constrained, so the first one will move to it. Repeat the process for the other side (click 3 times on element to be moved > click 3 times on constraint).

Here's a third video, where I can't get the bspline to make it tangent without rotating it. Making the first tangengy works fine, however for the second time it rotates it without my consent. Any idea why this happens and how can I fix it? This behaviour is so inconsistent: