While it is true that the selector in a data-target attribute is a jQuery selector, the data-api specification for this plugin provides no means of referencing back to this in the scope of execution (see lines 147-153 in bootstrap-collapse.js for its use).
However, I would like to offer another alternative approach, which is to extend the data-api with your own custom toggle specifier. Let’s call it collapse-next.
JS (see update note)
$('body').on('click.collapse-next.data-api', '[data-toggle=collapse-next]', function (e) {
var $target = $(this).parent().next()
$target.data('collapse') ? $target.collapse('toggle') : $target.collapse()
})
HTML
<a class="accordion-toggle" data-toggle="collapse-next">
JSFiddle (updated)
Downside here is that it’s a rather tightly coupled approach, since the JS presumes a specific structure to the markup.
Note about IE issues
As @slhck pointed out in his answer, IE9 and under apparently fail on the first click when using an earlier revision of my answer. The cause is actually not an IE issue at all, but rather a Bootstrap one. If one invokes .collapse('toggle') on a target whose Carousel object is uninitialized, the toggle() method will be called twice – once during initialization and then again explicitly after initialization. This is definitely a Bootstrap bug and hopefully will get fixed. The only reason it doesn’t appear as a problem in Chrome, FF, IE10, etc, is because they all support CSS transitions, and hence when the second call is made it short-circuits because the first one is still active. The updated workaround above merely avoids the double-call problem by checking for initialization first and handling it differently.