I do not know your specific scenario, but it looks like that you are attempting to provide some kind of "intelligency" or "auto-configuration" in your client - such as that the client would find a node named "FIM" in the OPC server, no matter which server it is or where in the tree the node it is located precisely. This may be a nice feature (and, in your scenario, it could be a real "must have" requirement), and is doable, but implemennting it has some disadvantages - such as the inefficiency I have described.
More typically, the client software is equipped with a feature that allows the user to select this node - either in some kind of confiiguration file, or interactively. The browsing methods on QuickOPC's EasyDAClient object can be used as basis for this. If the client is WinForms app or can at least invoke WinForms, it can use BrowseItemsForm from OpcLabs.EasyOpc.DataAccess.Forms to do this, without programming the internals of the user interface.

It looks like that you are looking for "find" or "search" capability. The browsing functions in OPC-DA (and consequently in QuickOPC) do not support this, at least not throughout the whole tree. In QuickOPC, you can always "emulate" searching by using the elementNameFilter and passing in either the precise node name or a match pattern; however this only works on a single parent node/level, so you already must know "where" to perform your search.
A search that would work throughout the whole address space tree is not supported in OPC-DA specifications, and therefore is only possible by traversing the tree until a match is found. As a general OPC address space tree may be quite large, this search operation would be inherently inefficient, but that may be acceptable if you definitely must have it. The shortest way to implement this is by writing a recursive function that looks for the match at given parent level, and if not found there, it tries the same on all child branches. You would then invoke the search by calling that function on a root level (an empty string for the parent).
Let me know if this explanation is sufficient to you. If you do not feel like writing this function, I can put together an example for you; in such case, please let me know which language you prefer (C#, VB.NET ...).
Kind regards,
ZZ