[AccessD] Slightly OT - network shares question

Given a corporate Windows network environment that has multiple domains, if
one assumed that the network was all connected thru routers, bridges,
switches, etc (I'm no network engineer), wouldn't be a very simple task to
make a share to connect one domain's server's folder to another ?
 
One Example: I was working with SQL Server on a server called XXX001 and it
was addressable from my login domain.
However, I could not BCP or even do an xp_cmdshell "DIR" to any of the
network shares that were made available to me.
I always got "access denied" from SQL Server.
Was this a network issue or a SQL Server role/rights issue ?
 
Another Example: Crystal reports was running from one server called YYY003.
I couldn't extract the report files to any of my login's network shares.
Couldn't they have easily introduced a permanent share on YYY003 to point to
a folder in one of the shares I could read/write to ?
This wasn't hard, correct ?